1. Field of the Invention
This invention relates to an image receiving medium for use with a sublimation-type thermal image transfer recording medium which comprises an image transfer layer containing a thermally sublimable dye.
2. Discussion of Background
The sublimation-type thermal image transfer recording method, which successfully achieves half-tone printing and full color hard copying, is growing in popularity these days. In this method, a thermal image transfer recording medium which comprises an image transfer layer containing a thermally sublimable dye is used in combination with an image receiving medium which receives the dye sublimed by heat applied from the back side of the recording medium.
In a dye receiving layer of the image receiving medium for use in the above recording method, thermoplastic resins which are highly receptive to the thermally sublimable dye, such as polyester resin, are employed. These resins, however, have low heat resistance, so that the dye receiving layer containing these resins tends to fuse and stick to an image transfer recording medium (a color sheet) when images are thermally recorded. In addition, the dye receiving layer once sticked to the color sheet cannot be smoothly separated from the color sheet when the recording is completed.
In order to overcome the above shortcoming, a releasing material such as silicone oil is generally incorporated into the dye receiving layer.
In the case where silicone oil is incorporated into the dye receiving layer, the releasing ability between the image transfer recording medium and the image receiving medium becomes high as the incorporation amount of the silicone oil is increased. When the silicone oil is employed in such an amount that the image receiving layer can easily peel off the image transfer recording medium, the adhesion between the dye receiving layer and a substrate, on which the dye receiving layer is formed, becomes weak. As a result, the dye receiving layer does not peel off the image transfer recording medium, but undesirably peel off the substrate when the thermal recording is completed.